


multiverse cosmic trip

by misbehavin



Category: Good Omens (TV), Supernatural
Genre: Alternate Universe, Boy King of Hell Sam Winchester, Castiel is a Little Shit, Crossover, Crowley is a Little Shit (Good Omens), Fluff, Flustered Castiel (Supernatural), Future Fic, Humor, Light Angst, M/M, POV Sam Winchester, Protective Aziraphale (Good Omens), Protective Castiel (Supernatural), Sam Winchester's Soul, Telepathic Bond, i guess, supergood
Language: English
Status: In-Progress
Published: 2020-12-02
Updated: 2020-12-06
Packaged: 2021-03-09 17:55:37
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,588
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27830380
Author URL: https://archiveofourown.org/users/misbehavin/pseuds/misbehavin
Summary: Castiel’s newfound power to jump through universes has come in handy these past few years, and Jack has learned enough of Sam’s leadership skills to be able to hold down the fort back home so Sam isn’t eager to come back so soon unless they return with everything they hoped to find: a list of spell books, including some botany spells (Sam’s taken to gardening and Cas has actual bees as pets, it’s a whole thing), and also the number and maybe, just maybe, the friendship of one infamous angel named Aziraphale. Stubborn researcher and investigator that he is, Sam had found him, and in the beginning Castiel was even looking forward to make acquantainces.It’s... not going according to plan.
Relationships: Castiel & Sam Winchester, Castiel/Sam Winchester
Comments: 14
Kudos: 50





	1. Chapter 1

**Author's Note:**

> yeah i saw that tumblr post and thought yknow what? cas and aziraphale antagonizing each other WOULD be funny. sam is my baby and tbh him being between this also seemed funny to me personally, so there you go

Sam doesn’t like the idea of being between angel hostility, no matter how subtle it is.

And there’s no other way to put it, whatever is going on. Castiel is standing at one side of the room, scanning the place, and Aziraphale, at the other side, is looking back and forth between them while he talks to Sam as if he thinks Cas might do something reckless and unforgivable to his precious collection if he takes his eyes off of him for a second too long.

It’s awkward. It’s so, _so_ awkward.

Castiel’s newfound power to jump through universes has come in handy these past few years, and Jack has learned enough of Sam’s leadership skills to be able to hold down the fort back home so Sam isn’t eager to come back so soon unless they return with everything they hoped to find: a list of spell books, including some botany spells (Sam’s taken to gardening and Cas has actual bees as pets, it’s a whole thing), and also the number and maybe, just _maybe_ , the friendship of one infamous angel named Aziraphale. Stubborn researcher and investigator that he is, Sam had found him and in the beginning, Castiel was even looking forward to make acquantainces.

It’s... not going according to plan.

Sam feels too big in this cozy bookshop and not that Cas would ever need his protection but, man, does he feel like a bodyguard who needs to be ready to throw himself between Cas and a flamed-sword at any moment now.

And the weird thing is that Aziraphale has been nothing but solicit. Sam has given him a list of what he’s looking for the first day they showed up, and now it’s not a secret him and Cas are not from _here_ , which isn’t the issue at hand unlike every other time they travel anywhere. Aziraphale is actually fascinated by that, and Sam has been in a good enough mood to answer some of his questions. The problem, it seems, like Sam said, is Angel Hostility. Or rather Gay Angel Hostility. Sam kind of had to hold back from laughing too much when he and Cas returned to their hotel that first night and Cas acted like he didn’t care or that he wasn’t slightly annoyed that the other angel was too _nice_ and too _fancy_ for hisliking, but now Sam wonders if the presence and proximity of two angels from different universes in the same place really does make them each uncomfortable on a molecular level. There’s an undeniable electric current in the air, almost like polar opposites pushing and pulling. Something alien, strange and invisible to human eyes, but so real it prickles Sam’s senses. Aziraphale and Cas don’t seem different to Sam in the ways that matter - they both obviously have big hearts and barely hide it - but Cas “rebel angel attitude” vibe seems to disrupt Aziraphale a bit too much. He’s jittery, keeps fixing his bowtie, and when Cas pulls out a book from a high shelf, opens a page at random then decides to put the book back after a moment, Aziraphale seems close to having a heart attack.

“Please,” he says in a high pitch. Sam is caught between worrying that this situation might get out of hand and wanting to really laugh at how ridiculous this situation is. “That is a very delicate rare edition from the 1700s. You can leave it on the table.”

Cas looks at the book in his hand, at Aziraphale, at Sam. He sets the book down carefully, face blank to anyone who doesn’t know him, then turns back around to continue perusing.

“So, Sam, as I was saying–” continues Aziraphale, as they walk further into the shop. “I can’t possibly give you my only edition of this. I went through a lot of trouble to get my hands on it and it would be a great loss if–”

“No worries, I totally get it,” says Sam. “Can I at least, I don’t know, borrow it? I’ll pay to borrow it, if that’s what it takes. It’s kind of important.”

Aziraphale fidgets, considering. “Perhaps you’d like to read it here? In the shop? For free, of course.”

Then he glances over Sam’s shoulder and sucks a breath. Sam doesn’t bother looking, because the next second the echo of a book hitting a wooden table very hard fills the room. Sam doesn’t even flinch, just scratches his forehead and crosses his arms, in a way bracing for the impact of said Gay Angel Hostility. Aziraphale is offended and Castiel is in a confrontational mood.

Great.

Aziraphale looks back at Sam with a terrible poker-face, “May I ask why is it so important?”

Sam sighs. He doesn’t divulge information so easily, but who even freaking cares? God’s dead, he killed the devil, he’s technically King of Hell, he and Cas are fathers to the last half-human half-angel person in their universe, they need this, and honestly out every other angel they’ve ever known Aziraphale is the only one who is clearly not a complete asshole.

“We’re trying to cure some demons,” Sam says, shrugging, like it’s not a big deal. (It is a big freaking deal). “It’s, uh, it’s complicated.”

Castiel pops up right beside them, holding a pile of books in his arms that are high enough to hit his chin.

Sam expects glass to shatter and the sizzling in the air to turn into a loud noise, almost like a siren, when he notices how close he is to Aziraphale, but nothing happens. At least, nothing he can tell.

“I thought we weren’t supposed to tell anyone about that.”

“It’s fine, Cas.”

“It’s sensible information.”

Aziraphale cuts in, forcing a friendly smile. “You can be assured I am a very good guardian of secrets.”

Castiel is not convinced.

Sam breathes out. “Look, if I can read through the books here and take notes that’s enough for me,” he pushes a strand of hair behind his ear with one hand, the other holding Cas’ shoulder to both anchor Cas and himself in their motives and in their partnership. He looks into Aziraphale’s eyes, “And if you think you can help us in any way we’d like that too, but before we tell you anything else, we need to know more about you too. Uh, it’s nothing personal, we, uh, we just had one too many bad experiences with other angels, y'know.”

“Oh. Of course, I understand,” he nods. “My partner will be stopping by later to help me close up,” he says, and it does sound like his partner is _his_ bodyguard. Sam can’t help but think this is still sort of funny though it didn’t stop veering into dangerous territory. “In the mean time, would you care for some tea, _Sam_?”

Cas squints at him, then puts himself between him and Sam. “Yes, we would love some tea.”

Now Sam feels the static shock him a little when the back of Cas’ shoulder grazes his chest. He smiles tighly at Aziraphale, and takes a deep breath before they follow him to a secluded area with comfortable chairs.

 _God_ , Sam thinks. _This is going to be a long freaking night._


	2. Chapter 2

Sam tries to tell Cas telepathically to _please, please quit it just for, like, fifteen minutes?_

It doesn't work because speaking to Castiel telepathically means, essentially, praying to him, and Cas has that particular way of communication shut down most of the time (it's distracting, he'd said once, to have other people's voices in his head when he's not in the mood to listen.) Even if he had that channel open, Sam doubts he _would_ listen anyway. He's too suspicious of Aziraphale to even consider calming down.

It's the third time they're here and the hot tea they've been sipping is doing nothing to soothe both angels' nerves or Sam's incoming headache.

Aziraphale is sitting upright and he took to mostly ignoring Castiel but it's in such a pointed, obvious way that it doesn't count. Cas, for his part, refuses to sit, so he's just standing by Sam's side holding his cup of tea with one hand, all business-like, while he seems to try to stare holes in Aziraphale's head. The static is sizzling so loud inside Sam's ears now that it takes him several attempts and a lot of focus to block the sound. He almost wishes his powers never returned.

"You understand, Sam," says Aziraphale. He'd been telling them a summarized version of his life for a couple of days. His partner didn't show up the other day or the next, so he went on to tell about how they met, became friends and confidants, and helped to save the world together. Between them, atop a center piece, sat a small pile of a few of the books Sam requested, and though he was tempted to grab them and start reading as soon as possible, he realized Aziraphale was making an effort to connect with them just like they'd hoped before they travelled all the way here. So Sam listened, and shared a bit too.

This was the agreed routine: they come to the bookshop and after some reading and annotating, they indulge in some late night tea drinking and some exchanging of stories. Well, Sam does most of the talking. Cas is still not willing to let his guard down any more than Aziraphale is willing to completely discard calling him _rude_ (it hasn't happened, but it's a matter of time at this point).

"I couldn't possibly let this world end, now, could I?" continues Aziraphale, "So many lives lost, such beauty, the food and my books, of course… Oh, I've been meaning to ask, did you… Was there an apocalypse in your universe as well?"

Sam fidgets and when he looks at Castiel, he's looking right back at him. It seems like he wants to say, _see, Sam, I told you befriending this person was a huge mistake._

Sam ignores him.

"Yeah," he admits, though he's beginning to share a bit of Cas' discomfort. "From what we know, it's a cosmic constant."

Aziraphale's eyes sparkle with interest.

"Really? I… I understand this may make you uncomfortable and I don't mean to impose, of course, but would you mind telling me more about your universe and your lives? And how overcame this… Well, this phophetized chaos?"

Sam takes a long sip of his tea. He's had a long journey since then, learning how to deal with his own feelings about it and the messy aftermath, just as Cas had as well. It's all healed now, their scars, especially after all subsequent apocalypses after that first one have been averted for good, forever, but Sam can't help but make a face when Castiel says, "Sam sacrificed himself by allowing the Devil to possess his body and saved the world by throwing himself down the deepest section of hell to imprison him."

"Oh."

For a moment, Aziraphale seems like he wants to say _I'm so sorry_ – not for asking, but that Sam has been through such horror. Sam appreciates that. When Aziraphale, instead of saying he's sorry, says, "How noble. And you, Castiel, saved him from damnation, I fathom?" Sam appreciates him even more.

Sam looks at Cas with a tiny smile, and bites down his lip to stop himself from smiling too wide when he notices Cas defenses tremble a little and then come back at full force. "Yes. I did."

"Against Heaven's orders, might I add," whispered Sam, against his cup.

Cas splutters. "It– It was the right thing to do."

"Of course," Aziraphale agrees, looking back and forth between them. He winks at Sam and the static shocks Sam again, and he doesn't stop grinning even as he spills some tea over himself. 

"It did not go well," Castiel says, and if he were the blushing kind, that's what would be happening right now. "I fought two archangels and they almost teared up Sam's soul apart."

Aziraphale seems to catch on Sam's discomfort about the subject and takes mercy on him while not giving up antagonizing Cas. He puts his cup down, his hands resting on his knees as he leans forward, "Oh, your rebel savior! _Very_ romantic."

Sam huffs and smiles wide, then, because Aziraphale is managing to be sincerely sweet even as he and Cas don't stop glaring daggers at each other. 

"Sam," starts Cas and looking up at him, lifting his eyebrows and biting down his lip, Sam knows there's no need for telepathy for Cas to understand what he is thinking.

Only for a second their gazes reciprocate, silently, what they have said out loud countless times. _Thank you, I forgive you, I believe in you, we are together in this, yes, I would kill and die for you all over again._

Then Castiel frowns, distracted, and the moment passes. "Something is wrong."

Sam leans forward in his chair, ready to stand up and in battle mode.

"Oh, it's my partner," Aziraphale says, a little bit nervous all of a sudden, standing up and leaving them. There's no sound of the door opening and closing, but Sam can tell someone came in.

The smell of sulfur fills the shop but it's soon overpowered by a smell that dissipates it, one so clean it's like the air got thin before returning to normal.

Inside Sam, something stirs. It's not fear and it's not violent, but it is raw. His incoming headache clears completely, but he feels a weight over his head pressing against his skull.

Castiel's eyes glow and Sam takes a brief glance into the bright blue light as they hear footsteps approaching. "Cas?"

"There's a demon here."

 _Shit_.

They breathe in and out in synch, ready for anything.

"It feels weird in here, have you been redecorating again?" a loud voice says nearby.

"The visitors I told you about are here. Please, play nice."

"Of course not, darling, you know I never–" 

They see each other at the same time. Sam _blinks_ and the person shifts into a snake, their glasses falling to the ground. The snake hisses, then shifts back into person-shape and stays on their knees, shaking their red hair out of their face.

" _What the bloody hell_? Angel, is this a trap?!"

"No, no, no," says Aziraphale, stepping in front of him to act as a shield, and so, so confused, "This is just one big misunderstanding!" He looks at Cas with pleading eyes, "What are you doing to him? Stop it!"

"We're not doing anything," assures Sam, glaring at those snake-like eyes.

"You didn't mention your partner was a demon," Castiel says. His eyes glow brighter, and his presence, greater, imposing.

"What?!" said partner keeps asking, struggling against invisible bounds. 

"I was building up to it!" Aziraphale doesn't seem to know what to do with his hands, but then he grabs Castiel's shoulder. Sam expects a real explosion in the fabric of reality but the only thing that happens is that the static freezes, like time. It's the strangest of sensations. "I only am asking and I will not ask twice, mister. Let him go!"

"I'm not doing anything."

Aziraphale takes his hand off of Castiel and turns his eyes to Sam, looking betrayed. "Sam?"

"I'm not doing anything either."

"Who the bloody hell did you bring home, angel?!" 

"This is Sam and Castiel, Crowley, the ones I told you about the other night! I don't know what is happening!"

"Well, for starters, I'm being forced to kneel!" Crowley all but spits. "To this kid, no less! Who the hell are you? You're an infant!"

It takes everyone a moment to realize Sam is the one being addressed. Standing with his shoulders squared and chin up, Sam takes a step around Cas and closer to Crowley, huffs and says, "Look and guess again."

Crowley tries to put his forehead to the ground and struggles some more, his arms shaking behind his back and his head bent touching his own chest. Then he finally looks up, obeying, and gasps, "Oh, dear Lo–"

"What is it?" asks Aziraphale. "Crowley, what–?"

Suddenly, the demon breaks into laughter. Angry, annoyed laughter, Sam can tell, but laughter nonetheless.

"Cas?" Sam asks, because honestly, he's confused too.

Castiel breathes out. "Fine. I was hiding your soul from _him_ ," he gestures.

"You were– What do you mean? How?"

Then something breaks, the sound rattling like fractured bone, and Aziraphale gasps too, staring at Sam.

"Oh," he says, eyes wide. "How odd. I've never met a human soul that old."

Sam swallows. Many years ago, he would have the instinct to hide, because he knows his soul was scarred from the times it's been flayed. But Cas healed him at least three thousand times over by now and he'd said that unlike Sam previously believed, his soul did not look like patchwork. Not anymore. It just looked different, regenerated. Almost holy. The only mark left is its age, which Cas told him is signaled by its brightness. Sam no longer feels like hiding, but he doesn't feel like showing off either. Still, he lets them look and understand his entirety.

Crowley stops snickering to take a deep breath. His teeth when he smiles are sharp, the irises of his yellow eyes reacting to a light Sam can't see, "May I stand up, your hellish Majesty?"

The weight on Sam's head makes perfect sense, suddenly, and he wants to roll his eyes. As if this whole situation – this multi-universe trip, Cas and Aziraphale not getting along – wasn't already ridiculous enough to begin with.

Aziraphale glances behind him. "Crowley?"

"Sam is King of Hell, where we come from," Castiel says, before Sam can even open his mouth to speak. His eyes are no longer glowing, though his stance hasn't changed. He's still ready to jump into a fight.

Aziraphale is taken aback. "You didn't tell me that."

"Well, we were building up to it," Cas retorts.

"Crowley, is it?" Sam cuts in. "Yes, you can stand up. But don't try anything funny."

"Wouldn't dream of it, my good sir."

As the demon puts his glasses back on, sprawls over Aziraphale's chair and Aziraphale breathes out in utter relief, Castiel's voice sounds inside Sam's head, _I think I may grow to like this one._

What a convenient time to join the telepathic conversation, Sam thinks, in secret. _Yeah? Why?_ he asks. _He respects you,_ Cas says. 

_And Aziraphale doesn't?_

_You know what I mean._

_No, I really don't, Cas._

Crowley clears his throat. "Nice to meet you, Castiel, is it? Yeah, yeah, anyway, so, my liege, has Aziraphale been boring you with all this nerdy stuff?"

"A little," Cas says and Sam gives him a look. _Really, Cas? Really?_

 _He_ is _boring us._

_No, he's not._

"Don't. Don't call me that. Just Sam is fine."

"Right, right, 'course. So, Just Sam," Crowley mocks, "how's Aziraphale treating you?"

"Sam."

Behind his glasses, Crowley rolls his eyes. " _Sam._ "

"Yeah, Aziraphale is great. Uh, it's been, great."

"Would you like some tea, darling?" Aziraphale asks, already pouring it on the cup he was using that Crowley is already picking up. 

Sam sits back down, but the awkwardness remains and he wonders if they should call it a night and go back to the hotel. To his surprise Cas sits on the arm of the chair, by his side, arms crossed. Sam skates his arms around his waist and Cas leans back against it. They're staying, then.

After taking a sip of his tea, Crowley moves to sit on the arm of the chair on the side close to the wall, giving room to Aziraphale to sit between his legs – one splayed with his foot touching the ground and the other behind Aziraphale's back.

The four of them sit in silence.

_This is taking too long._

_Cas, chill out._

_No_.

"So where is the spell about curing demons?"

Sam holds his breath and squeezes him. _Goddammit, Cas._

"What?" Crowley frowns, his threatening smiley façade shattering.

"We don't know how things are here, but where we're from, demons are human souls. We're trying to save who we think should be saved."

"Oh, that is… That is indeed very noble, Sam. I knew I didn't make a mistake trusting you," affirms Aziraphale, smiling kindly. "And what about fallen angels, if you don't mind me asking?"

"Condemned to roam the Earth and die as mortals."

"Yuck," Crowley mutters.

Sam snorts. "Yeah," he agrees. "You can see what kind of problem I'm facing, then."

Aziraphale looks like he wants to cry. "They go to hell after they die?"

"They do now. But anyway," Sam shrugs. God, he needs to sleep. Only talking about all of this is tiring. "The whole thing is a bureaucratic mess."

"Get cosmic lawyer then," suggests Crowley and Sam is the one who almost breaks into laughter now.

"I, uh, I kind of almost was one. A lawyer, I mean."

"Ah, this conversation keeps getting more and more interesting," comments Aziraphale.

"Yes, we are very interesting people," murmurs Castiel. Wow, Sam thinks, squeezing his waist again. He doesn't get why he keeps getting surprised at how much Cas really does not give a single fuck.

"So you are," Crowley agrees, cup of tea balanced on his knee and his other hand holding, gently, the back of Aziraphale's neck. If he had his glasses off, Sam is sure he'd be squinting. "So you are."

  
  
  
  
  
  
  
  


**Notes for the Chapter:**

> I couldn't see this happening any other way and i will not apologize.  
> also, is Cas jealous? we just don't know, but it WOULD be funny if that's one of the reasons he's being Like That

**Author's Note:**

> cas: *murder eyes*  
> sam, worried for the other person, for cas, for their mission: babe. babe not now please


End file.
